Spinal fixation tool set and method

ABSTRACT

A tool set for implanting a rod in a human spine in conjunction with bone screws includes a pair of end guide tools that receive opposite ends of the rod in channels and under manipulation by a surgeon facilitate transport of the rod toward the bone screws attached to the guide tools. Each end guide tool includes a laterally extending, rigid, rod holding structure located near a bottom surface thereof. Intermediate guide tools having pass-through slots are utilized to guide the rod to the bone screws at intermediate locations.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional continuation of U.S. application Ser.No. 10/996,289, filed Nov. 23, 2004.

BACKGROUND OF THE INVENTION

The present invention relates to apparatuses and methods for use inperforming spinal surgery and, in particular, to tools and methods ofusing such tools, especially for percutaneously implanting spinal screwsand for implanting a rod for spinal support and alignment, usingminimally invasive techniques.

For many years, spinal osteosynthesis apparatuses have been utilized tocorrect spinal deformities, injuries or disease. In such procedures,elongate rods are surgically attached to vertebrae of the spine toprovide support and/or to realign or reposition certain vertebrae. Suchrods are secured to vertebrae utilizing bone screws and other spinalimplants. In order to reduce the impact of such surgery on the patient,a desirable approach is to insert such implants percutaneously or withsurgical techniques that are minimally invasive to the body of thepatient.

Problems arise when implantation tools designed for traditional surgerythat is highly invasive are utilized in percutaneous surgery. The toolsmay be bulky, oversized or have irregular surfaces or protrusions. Aprojecting actuator arm or fastening member may be useful with respectto the spinal screw implantation process or the rod reduction process,but there is insufficient clearance to use such structure and/or suchstructure may produce additional invasive trauma which the percutaneoussurgery is attempting to avoid.

A percutaneous procedure also presents a problem with implantation ofrods that are elongate and have historically required a long incisionand open wound in order to provide for the length of the rod and thespace required for the surgeon's hands to manipulate the rod. Suchproblems are then compounded by the implants and insertion tools usedwith the rod.

Consequently, it is desirable to develop apparatuses and techniques thatallow for the insertion of bone screws, the insertion and reduction of arod into the bone screws and the securing of the rod to the bone screwswith significantly less invasion into the body of the patient and withminimal surgical incision of the skin over the operational site.

SUMMARY OF THE INVENTION

A tool set according to the invention is provided for percutaneouslyimplanting bone screws and an associated spinal rod in a patient. Thetool assembly includes first and second end guide tools, each guide toolhaving an elongate body, an outer surface and a channel with a lateralopening extending through the outer surface and along a longitudinalaxis an entire length of the guide tool. The channel and channel openingare sized and shaped for side loading and receiving of an end of the rodand also for receiving spinal implant fasteners and cooperatingmanipulation tools.

Near a bottom of the end guide tool body is a rigid, rod holdingstructure disposed opposite the lateral opening. The rigid rod holdingstructure projects laterally outwardly from the elongate body outersurface, and is sized and shaped to closely receive and abut against anend of the rod. The rod holding structure holds the rod end at alocation outside of the spinal implant. The structure preferablyincludes a pair of spaced arms extending laterally about the end guidetool body. The guide tool body defines an opening disposed adjacent thearms, with the opening sized and shaped to receive the rod therethrough.

A tool set according to the invention may also include one or moreintermediate guide tools, each having first and second elongate legsdefining an elongate through-slot sized and shaped for receiving a rodtherethrough.

Both the end guide tools and the intermediate guide tool have opposedspinal implant engaging structure disposed near a bottom thereof. Theimplant engaging structure of the illustrated embodiment includes firstand second opposed radially inwardly projecting pins. The pins are sizedand shaped to be received in cooperating apertures in the spinal implantfor releaseable attachment thereto. Preferably each pin has an upwardlyprojecting lip sized and shaped to be received in an upwardly projectinginner recess of the spinal implant aperture, allowing for a snap-on,snap-off cooperation between the guide tool and the spinal implant.

To provide such a snap-on, snap-off cooperation between the end guidetool and a spinal implant, each end guide tool includes a narrow slotdisposed opposite the lateral opening. The narrow slot and lateralopening cooperate to allow manual flexing of the guide tool body toincrease a distance between the first and second pins during insertionand removal of the guide tool on the spinal implant.

A tool set of the invention further includes a driving tool attachableto both the end and intermediate guide tools. The driving tool isreceivable in the tools and operably attachable to the spinal implantfor rotating and driving the implant into bone. In an embodimentaccording to the invention, the end and intermediate guide tools haveouter guide and advancement structure, such as a thread at an upperportion of the tool body. The driving tool has a fastener, a stem and adriving structure disposed at a lower end of the stem, the drivingstructure for rotating and driving the implant into bone. The fasteneris freely rotatable with respect to the stem and includes an inner guideand advancement structure that is rotatingly mateable with the outerguide and advancement structure of the guide tools.

The tool set further includes a rod pusher attachable to both the endand intermediate guide tools. The rod pusher includes a sleeve and adriving end. The sleeve is receivable over the elongate guide tool bodyand operably attachable to the body for rotating thereabout, with therotational movement of the sleeve also translating the driving end alongthe body. The rod pusher includes an inner guide and advancementstructure mateable with the outer guide and advancement structure of therespective guide tool.

The tool set may also include an elongate torquing tool having a handleand a stem receivable in the channel of both the end and intermediateguide tools and attachable to an implant fastener. Cooperating with thetorquing tool is an elongate anti-torque tool having a handle and asleeve receivable over the respective guide tool body. The sleeve issized and shaped to seat upon and abut against a rod at either side ofthe guide tool body, resisting any rotational movement of theanti-torque tool relative to the end guide tool.

A vertebral support rod implantation kit according to the invention,adapted for use with a plurality of vertebrae, includes a plurality ofpolyaxial bone screws, each bone screw being adapted for implantation inone vertebra, each of the bone screws having an attachment structure.The kit also includes an elongate rod having first and second ends, therod sized and shaped to extend between a pair of end bone screws of theplurality of bone screws. The kit further includes a plurality ofclosure tops with each closure top being sized and shaped to mate with arespective bone screw and capture or retain the elongate rod within acavity or channel defined by the respective arms of the bone screw.Additionally, the kit includes a pair of end guide tools, and mayinclude one or more intermediate guide tools, each guide tool beingattachable to the driver and the rod pusher previously described herein.

In a method according to the invention, a spinal fixation tool assemblyis assembled by first attaching a bone screw head of a spinal implantscrew to a mating attachment structure disposed at a first end of anelongate guide tool implant engaging member, the guide tool defining alaterally opening channel and having a second attachment structuredisposed at a second end thereof. A driver is then inserted in the guidetool and attached spinal implant screw. The driver includes a fastenerthat is rotated in a first direction to mate the driver with the secondattachment structure on the guide tool and thereby engage the driverwith the spinal implant screw.

A method according to the invention includes the steps of inserting theattached driver, guide tool and spinal implant screw into an incision,especially a minimally invasive incision sized to snugly or closelyreceive the assembled tools and bone screw, and into contact with avertebra, followed by turning the driver handle. By turning the handle,only the driver and the screw are rotated, driving the spinal implantscrew into the vertebra.

Further method steps according to the invention include detaching thedriver from the guide tool and attaching a rod pusher onto the guidetool by placing the rod pusher sleeve onto the guide tool and rotatingthe sleeve. The rod is then guided into and through all the guide toolchannels. The sleeve is rotated, advancing a rod pushing end toward thebone screw and pushing the rod toward the screw until the ends of therod are in contact with the laterally extending, rigid rod holdingstructure disposed near the bottom of the end guide tools. The methodfurther includes the step of fixing closure tops to the spinal implantscrew heads, with the rod being captured between the spinal implantscrew and the closure top.

OBJECTS AND ADVANTAGES OF THE INVENTION

Therefore, objects of the present invention are: to provide a compacttool assembly for supporting and installing bone screws and otherimplants with minimal surgical invasion to the patient; to furtherprovide a set of tools for implanting a spinal rod for support oralignment along a human spine with minimal surgical invasion of thepatient; to provide such a set of tools including a pair of end toolguides for slidably guiding opposed ends of the rod toward end bonescrews attached to the end guide tools; to provide such a set of toolsincluding intermediate guide tools for each intermediate bone screw thatguide the rod in slots therethrough to respective bone screws; toprovide such a set of tools including rod and implant fastener orclosure top installation tools for assisting in securing the rod in thebone screws; to provide such a set of tools wherein the guide tools areeasily attached to and disengaged from the bone screws; to provide sucha set of tools wherein the guide tools, guide tool supports orstabilizers, deployment tools, rod reduction tools, bone screwinstallation tools and implant fastener installation tools are alleasily aligned, positioned, and engaged, if necessary, with respect tothe bone screw and are disengaged from the bone screw and other tools inthe installation assembly by manual manipulation of the surgeon outsidethe patient's skin; to provide a method of implanting a rod into bonescrews within a patient with minimal surgical invasion of the patient;to provide such a method utilizing the previously described tools forpercutaneous implantation of such a rod; and to provide such a set oftools and methods that are easy to use and especially adapted for theintended use thereof and wherein the tools are comparatively inexpensiveto produce.

Other objects and advantages of this invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings wherein are set forth, by way of illustration and example,certain embodiments of this invention.

The drawings constitute a part of this specification and includeexemplary embodiments of the present invention and illustrate variousobjects and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of an end guide tool according to theinvention.

FIG. 2 is a side elevational view of the end guide tool of FIG. 1.

FIG. 3 is a rear elevational view of the end guide tool of FIG. 1.

FIG. 4 is a front elevational view of an intermediate guide toolaccording to the invention.

FIG. 5 is a side elevational view of the intermediate guide tool of FIG.4.

FIG. 6 is a rear elevational view of the intermediate guide tool of FIG.4.

FIG. 7 is an enlarged bottom plan view of the intermediate guide tool ofFIG. 4.

FIG. 8 is an enlarged partial cross-sectional view taken along the line8-8 of FIG. 4.

FIG. 9 is an enlarged cross-sectional view taken along the line 9-9 ofFIG. 8.

FIG. 10 is an enlarged exploded perspective view of a polyaxial bonescrew of the invention including a shank, head, retaining ring and nut.

FIG. 11 is an enlarged cross-sectional view of the head, taken along theline 11-11 of FIG. 10, illustrating the retaining ring being insertedinto the head.

FIG. 12 is an enlarged cross-sectional view of the head similar to FIG.11, shown with a retaining ring of FIG. 10, shown in cross-section,disposed in the head and seated on the shank upper end, and also shownpartially exploded with a nut of FIG. 10, prior to the nut beingrotatably inserted onto the shank upper end.

FIG. 13 is an enlarged cross-sectional view of the head similar to FIG.11, shown with an assembled shank, retaining ring and nut, and furthershowing the intermediate tool in cross-section, taken along the line13-13 of FIG. 5, in a first stage of a snap-on attachment to the head.

FIG. 14 is an enlarged cross-sectional view similar to FIG. 13 showingan intermediate stage of the snap-on attachment of the intermediate toolto the head.

FIG. 15 is an enlarged cross-sectional view similar to FIG. 14, showinga final stage of the snap-on attachment of the intermediate tool to thehead.

FIG. 16 is a fragmentary front elevational view of a driver according tothe invention.

FIG. 17 is a fragmentary side elevational view of the driver of FIG. 16.

FIG. 18 is a fragmentary rear elevation view of the driver of FIG. 16having a portion shown in cross-section, taken along the line 18-18 ofFIG. 17.

FIG. 19 is a reduced and fragmentary view of the driver of FIG. 18 showncooperating with the intermediate tool and attached bone screw (theintermediate tool shown in cross-section, similar to FIGS. 13-15, buttaken along an entire length thereof).

FIG. 20 is an enlarged and fragmentary view, similar to FIG. 19, showingthe driver spaced from the shank assembly.

FIG. 21 is an enlarged and fragmentary view, similar to FIG. 20, showingthe driver engaging the shank assembly.

FIG. 22 is a partial, fragmentary and generally schematic view of apatient's spine showing a driver of FIG. 16 cooperating with an end toolof FIG. 1 with attached bone screw being guided toward a threaded borein a vertebra in an early stage of a method according to the invention.

FIG. 23 is a front elevational view of a rod pusher according to theinvention.

FIG. 24 is a side elevational view of the rod pusher of FIG. 23.

FIG. 25 is a cross-sectional view taken along the line 25-25 of FIG. 23.

FIG. 26 is an enlarged perspective view of a spinal implant fasteneraccording to the invention.

FIG. 27 is a reduced exploded view of an assembly according to theinvention including the implant fastener of FIG. 26 attached to amanipulation tool, the rod pusher of FIG. 23 and the intermediate guidetool of FIG. 4 with attached bone screw.

FIG. 28 is a reduced view, showing the manipulation tool and implantfastener of FIG. 27 inserted in a rod pusher, intermediate guide tooland bone screw assembly, the rod pusher in cross-section, taken alongthe line 28-28 of FIG. 24, the intermediate guide tool in cross-section,similar to the line 13-13 of FIG. 5, but extending along the entirelength of the tool, and the bone screw in front elevation.

FIG. 29 is a partial and generally schematic view of a patient's spine,showing a pair of end tools with a rod contained therebetween and a pairof intermediate tools of the present invention with one of theintermediate tools shown with an attached rod pusher in a rod reductionapplication, with one of the end guide tools shown partially cut-away,illustrating an implant fastener manipulation tool disposed within theend tool and cooperating with an implant fastener, the tools beingutilized in an early stage of rod implantation to guide the rod towardthe bone screws.

FIG. 30 is an enlarged, partial and generally schematic cross-sectionalview taken along the line 30-30 of FIG. 29.

FIG. 31 is an enlarged and partial view, similar to FIG. 28, furthershowing the implant fastener in cross-section, taken along the line31-31 of FIG. 26, with the implant fastener installed in the bone screwand the manipulation tool being moved away therefrom.

FIG. 32 is a partial, front elevational view of an anti-torque toolaccording to the invention.

FIG. 33 is a partial, rear elevational view of the anti-torque tool ofFIG. 32.

FIG. 34 is a reduced, partial elevational and exploded view of anassembly according to the invention, including a torquing tool, theanti-torque tool of FIG. 33 and the end guide tool of FIG. 3, furthershown with a rod, bone screw and implant fastener.

FIG. 35 is an enlarged and partial view of the assembly of FIG. 34, withportions removed to show the detail thereof, shown prior to torquing ofthe implant fastener.

FIG. 36 is an enlarged and partial view similar to FIG. 35 shownsubsequent to torquing, with the torquing tool removing a break-off headof the implant fastener.

FIG. 37 is a partial and generally schematic view of a patient's spine,similar to FIG. 29, with one of the end guide tools removed and theother end guide tool shown partially cut-away, illustrating the rodinstalled in the bone screws and abutting against a holding structure ofthe end tool.

FIG. 38 is an enlarged cross-sectional view taken along the line 38-38of FIG. 37 with the bone screw shown in front elevation.

DETAILED DESCRIPTION OF THE INVENTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure.

With reference to FIGS. 1-38, the reference letter T generallydesignates a tool set according to the present invention made up of anumber and variety of tool assemblies for use in installing a set ofbone screws 1 into vertebrae 2, followed by the installation of anorthopedic spinal rod or longitudinal member 3 into the bone screws 1along a patient's spine 4 in a process according to the presentinvention.

With special reference to FIGS. 10-12 and 38, the reference numeral 1generally represents a polyaxial bone screw apparatus or assemblyutilized in the present invention. However, it is foreseen that avariety of bone screws may be utilized with the other components of thetool set T of the invention, as will be discussed more fully below. Inthe illustrated embodiment, the bone screw assembly 1 includes a shank6, a head 7, a retaining structure or ring 8, a fastener or nut 9 and aclosure structure or top 10. The nut 9 includes an inner raised helicalrib or thread 12, an external hexagonally faceted surface 13 and aslightly radiused or curved top surface 14. The shank 6 is elongate andhas a lower body 15. As illustrated in FIG. 19, the shank body 15 has ahelically wound bone implantable thread 17 extending from near a top 18to near a tip 19 of the body 15 and extending radially outwardtherefrom. During use, the body 15 utilizing the thread 17 is implantedinto the vertebra 2, as is shown in FIG. 22. The shank 6 also has anelongate axis of rotation A. It is noted that the reference to the wordstop and bottom, upper and lower, and the like, as used herein refers tothe alignment shown in the various drawings, as well as the normalconnotations applied to such devices, and is not intended to restrictpositioning of the bone screw 1 and other tools of the tool set T of theinvention in actual use.

Extending axially outward and upward from the shank body 15 is a neckregion 20, substantially hyperboloid in configuration, having a minimumradius smaller than a radius at the top 18 of the body 15. Furtherextending axially and outwardly from the neck 20 is a capture structure21 providing a connective or capture portion of the shank 6. The neckregion 20 provides a space between the capture structure 21 and theshank body 15, operably also spaced from the bone or vertebra 2 foradjoining with the head 7. The capture structure 21 has a radially outercylindrical surface 22 with an external helically wound guide andadvancement structure illustrated as a rib or thread 24. The thread 24is located near an upper end 25 of the shank 6 and is sized and shapedto receive the threaded nut 9. Although a simple raised helical rib orthread 24 is shown in the drawings, it is foreseen that other structuresincluding other types of threads, such as buttress and reverse anglethreads, and non-threads, such as helically wound flanges withinterlocking surfaces, may be used in alternative embodiments of thepresent invention.

Also located at the shank upper end 25 is a centrally located, axiallyextending and upwardly directed projection or dome 29 that is centrallyradiused so as to have a first radius. The projection 29 is preferablycurved or dome-shaped as shown in the drawings, for positive engagementwith the rod 3, when the bone screw assembly 1 is assembled, as shown inFIG. 38, and in any alignment of the shank 6 relative to the head 7. Incertain embodiments, the surface 29 is smooth. While not required inaccordance with practice of the invention, the domed surface 29 may bescored or knurled to further increase frictional engagement between thedome 29 and the rod 3. Also as illustrated in FIG. 38, preferably thenut top surface 14 has the same or similar first radius as the dome 29to provide a continuous, positive engagement with the rod 3 at anyalignment of the shank 6 with respect to the head 7.

Disposed between the neck 20 and the threads 24 of the capture structure21 is a smooth cylindrical surface 30 terminating at a lower shoulder31. The shoulder 31 is disposed adjacent to the neck 20 and includes anannular seating surface 32 oriented perpendicular to the axis ofrotation A. The surface 32 extends outwardly radially from thecylindrical surface 30. The shoulder 31 divides the smooth cylindricalsurface 30 from the neck 20 of the shank 6. The cylindrical surface 30has a reduced inner radius relative to a maximum radius of the neck 20adjacent the shoulder 31. The cylindrical surface 30 is sized and shapedto slidingly mate with the retaining ring 8 and centrally position theretaining ring 8 in alignment with the shank axis A and also generallycentrally within the head 7, as will be discussed more fully below.

The head 7 has an outer profile that is substantially cylindrical inshape, as shown in FIG. 10. However, the head 7 is not a solid cylinder,but rather includes inner openings, a cavity and a channel describedmore fully hereafter, and being substantially symmetrical with respectto an axis of rotation B of the head 7. The head 7 includes a base 33integral with a pair of upstanding arms 34 and 35. The arms 34 and 35form a U-shaped channel 38 therebetween, defined in part by a lower seat39 having substantially the same radius as the rod 3 for operably snuglyreceiving the rod 3. Each of the arms 34 and 35 has an interior surface41 that includes a partial, helically wound guide and advancementstructure 42. In the illustrated embodiment, the guide and advancementstructure 42 is a partial helically wound flangeform configured to mateunder rotation with a similar structure on the closure top 10, asdescribed more fully below. A suitable locking guide and advancementstructure of this type is disclosed in U.S. Pat. No. 6,726,689 from Ser.No. 10/236,123 which is incorporated herein by reference. However, it isforeseen that the guide and advancement structure 42 could alternativelybe a V-shaped thread, a buttress thread, a reverse angle thread or otherthread like or non-thread like helically wound advancement structure foroperably guiding under rotation and advancing the closure top 10 betweenthe arms 34 and 35.

Tool engaging apertures 44 are formed on outer surfaces of the arms 34and 35 for holding the head 7 during assembly and also during theimplantation of the shank body 15 into the vertebra 2. The apertures 44are disposed opposite one another and each include respective upwardlyprojecting, hidden inner recesses 45 for cooperating with complimentarybone screw holding components of guide tools according to the invention,discussed more fully below. It is noted that the apertures 44 and thecooperating guide tool holding components may be configured to be of avariety of sizes and locations for attachment to the guide tool alongany of the surfaces of the arms 34 and 35.

A chamber or cavity 47 is located within the head base 33 that opensupwardly into the U-shaped channel 38. The cavity 47 is defined in partby a partially spherically shaped inner surface 48, at least a portionof which forms a partial internal hemispherical seat 49. The surface orseat 49 is sized and shaped for mating with the retaining ring 8, asdescribed more fully below. The hemispherically shaped surface 49 has asecond radius associated therewith. At the opening into the U-shapedchannel 38, the cavity 47 is defined in part by a discontinuous shoulderor upper coplanar seat 50 disposed on each of the arms 34 and 35extending radially and substantially perpendicular to the axis B, asillustrated in FIG. 11.

At a bottom of the base 33, the cavity 47 communicates with asubstantially circular bore 52 opening to an exterior of the base 33.The bore 52 is coaxial with the rotational axis B of the head 7. Thebore 52 is defined at least in part by a restrictive neck 54 that has aradius that is smaller than an outer radius of the ring 8, as will bediscussed further below, so as to form a restrictive constriction at thelocation of the neck 54 relative to the retaining ring 8 to prevent thering 8 from passing between the cavity 47 and the lower exterior of thebase 33 of the head 7. However, it is foreseen that the retaining ring 8could be compressible and thus loadable through the neck 54 and thenallowed to expand and fully seat in the spherical seating surface 49. Abevel 55 extends between the neck 54 and the bottom exterior of the base33.

The retaining ring 8 is used to retain the capture structure 21 of theshank 6 within the head 7. The retaining ring 8, best illustrated inFIGS. 10-12, has an operational central axis that is the same as theelongate Axis A associated with the shank 6, but when the retaining ring8 is separated from the shank 6, the axis of rotation is identified asaxis C, as shown in FIG. 10. The ring 8 has a central bore 57 disposedalong the central axis C, with the central bore 57 passing entirelythrough the retaining ring 8 from a top surface 58 to a bottom surface59 thereof. The bore 57 is sized and shaped so that the ring 8 fitssnugly but slidably over the shank capture structure 21 and outercylindrical surface 30 in such a manner as to allow sliding axialmovement therebetween under certain conditions, as described below. Asurface 60 defining the bore 57 is smooth and has a radius configured tobe only slightly larger than an outer radius of the cylindrical surface30, providing for slidable mating engagement between the surface 60 andthe surface 30. As will be described subsequently in more detail, theshank capture structure 21 is uploadable into the head 7, and throughthe ring 8 that is already disposed in the head 7, by axially slidingthe capture structure 21 through the ring central bore 57 until the ringbottom surface 59 is seated on the annular surface 32 of the shank 6, asillustrated in FIG. 12.

To secure the retaining ring 8 within the head 7, the inner thread 12 ofthe nut 9 is mated to the outer thread 24 of the capture structure 21.Similar to the thread 24, although a simple raised helical rib or thread12 is shown in the drawings, it is foreseen that other structuresincluding other types of threads, such as buttress and reverse anglethreads, and non-threads, such as helically wound flanges withinterlocking surfaces, may be used in alternative embodiments of thepresent invention.

The mating of the nut inner thread 12 and the capture end outer thread24 is aided by the shoulder 50 of the head 7. As illustrated in FIG. 12,after receiving the retaining ring 8 thereon, the shank 6 may be movedupwardly, until the top surface 58 of the ring 8 abuts the flat shoulder50 at each of the arms 34 and 35, providing a relatively stable positionfor receiving the nut 9. The nut 9 is then top loaded into the head 7through the channel 38, placed in axial alignment with the shank 6,lowered onto the shank capture structure 21, and rotated in a clock-wisedirection when viewed from above. The nut 9 may be installed with asocket-type tool, similar to a driver 112 shown in FIGS. 16-21 utilizedfor implanting the bone screw assembly 1 in a vertebra 2, and discussedmore fully below. The socket-type tool mates with the external facetedhexagonal surface 13, and is rotated and driven downward until thebottom surface 59 of the ring 8 abuts the annular surface 32 of thelower shoulder 31 and is frictionally fixed thereto. When the ring 8abuts the annular surface 32, the dome 29 protrudes axially above thenut 9 with the nut top surface 14 disposed contiguous to the dome 29.The dome 29 and the top surface 14 preferably forming a continuouscurved perimeter, the surface 14 extending the first radius of the dome29, as illustrated in FIG. 13.

To further ensure frictional engagement between the nut 9 and thecapture structure 21 of the shank 6, the nut 9 includes one or moreweakened areas 61 located along the faceted surface 13 thereof, as shownin FIG. 12. A set tool (not shown) having a tip passes between theupstanding arms 34 and 35 of the head 7 and pushes against the nut 9 atthe weakened area 61, the tip indenting the area 61, forming anindentation or deformation on the nut surface, and also pressing againstthe thread 12 and/or the thread 24, creating or causing a deformedthread portion or portions, interlocking the threads 12 and 24, which inturn lodges the ring 8 in a fixed position with respect to the shank 6.The deformed thread portion or portions prevent counter-clockwiserotation of the nut 9 with respect to the shank capture structure 21,and thus prevents the nut 9 and the ring 8 from migrating up and off theshank upper end 25 and into the channel 38, away from the desiredposition within the head 7.

The ring 8 has a radially outer partially hemispherically shaped surface65 sized and shaped to slidingly mate with the partially hemisphericallyshaped seating surface 49. The surface 65 has a third radiusapproximately equal to the second radius associated with the seatingsurface 49. The third radius of the ring surface 65 is substantiallylarger than the first radius associated with the dome 29 and alsosubstantially larger than an inner radius of the neck 54. Although notrequired, it is foreseen that the outer partially spherically shapedsurface 65 may be a high friction surface such as a knurled surface orthe like.

Preferably, the retaining ring 8 is constructed of a metal or othermaterial having sufficient resilience and elasticity so as to allow thering 8 to radially expand slightly outward by downward pressure of thenut 9 on the top surface 58 and under pressure from structure above, aswill be discussed further below. This produces a slight outward radialexpansion in the ring 8 at the shoulder 31 of the shank 6.

The longitudinal member or elongate rod 3 can be any of many differenttypes of implants utilized in reconstructive spinal surgery and thelike, but is normally a cylindrical elongate structure having a smooth,cylindrical surface 66 of uniform diameter. The rod 3 is preferablysized and shaped to snugly seat near the bottom of the U-shaped channel38 at the lower seat 39 and, during normal operation, will be positionedslightly above a bottom of the channel 38. In particular, the rod 3normally engages the shank dome 29, as illustrated in FIG. 38, and urgesagainst the dome 29 and, consequently, downwardly against the shank 6when the bone screw assembly 1 is fully assembled. For this to occur,the shank domed surface 29 must extend at least slightly into the spaceof the channel 38 when the retaining ring 8 is snugly seated in thelower seat 49 of the head cavity 47. The shank 6 and retaining ring 8are thereby locked or held in position relative to the head 7 by the rod3 firmly pushing downward on the shank domed surface 29. At certaindegrees of inclination of the shank 6 with respect to the head 7, therod 3 may push downward on both the domed surface 29 and a portion ofthe nut top surface 14.

With particular reference to FIGS. 26, 31 and 38, the implant fasteneror closure top 10 can be any of a variety of different types of closurestructures for use in conjunction with the present invention withsuitable mating structure on the inner or outer surfaces of theupstanding arms 34 and 35 of the bone screw head 7. The closure top 10is rotatably received between the spaced arms 34 and 35.

The illustrated closure top 10 has a generally cylindrical shaped base67 with an upwardly extending break-off head 68. The base 67 includes ahelically wound guide and advancement structure 71 that is sized, shapedand positioned so as to engage the guide and advancement structure 42 onthe arms 34 and 35 to provide for rotating advancement of the closurestructure 10 into the head 7 when rotated clockwise and, in particular,to cover the top or upwardly open portion of the U-shaped channel 38 tocapture the rod 3, preferably without splaying of the arms 34 and 35.

The base 67 further includes a lower point or projection 72. Theprojection 72 provides for increased friction against the rod 3. Theclosure structure 10 operably biases against the rod 3 at and near theprojection or point 72 by advancement and applies pressure to the rod 3under torquing, so that the rod 3 is urged downwardly against the shankdomed top surface 29 that extends into the channel 38. Downward biasingof the shank top surface 29 operably produces a frictional engagementbetween the rod 3 and the surface 29 and also urges the retaining ring 8toward the base 33 of the head 7, so as to frictionally seat theretaining ring spherical surface 65 fixedly against the partial internalspherical seating surface 49 of the head 7, also fixing the shank 6 andretaining ring 8 in a selected, rigid angular position relative to thehead 7.

The closure structure break-off head 68 is secured to the base 67 at aneck 73 that is sized and shaped so as to break away at a preselectedtorque that is designed to properly seat the retaining ring 8 in thehead 7. The break-off head 68 includes an external faceted surface 75, acentral bore 77 and a pass-through slot 78 for receiving a manipulationtool 118 more fully described below. The faceted surface 75 is sized andshaped to receive a conventional mating socket type head of a torquingtool 122 to rotate, drive and torque the closure structure 10, also morefully described below. It is foreseen that different driving heads orother methods of driving the closure top 10 may be utilized with certainembodiments of the invention, including non-break-off closure topdesigns.

The closure structure 10 also includes removal tool engagement structurewhich in the present embodiment is in the form of a hex-shaped andaxially aligned aperture 81 disposed in the base 67, as shown in FIGS.31 and 38. The hex aperture 81 is accessible after the break-off head 68breaks away from the base 67. The aperture 81 is coaxial with thehelically wound guide and advancement structure 71 and is designed toreceive a hex tool, of an Allen wrench type, into the aperture 81 forrotating the closure structure base 67 subsequent to installation so asto provide for removal thereof, if necessary. Although a hex-shapedaperture 81 is shown in the drawings, the tool engagement structure maytake a variety of tool-engaging forms and may include one or moreapertures of various shapes, such as a pair of spaced apart apertures,or a left hand threaded bore, or an easy-out engageable step down bore,a hexalobular aperture (for example, sold under the TORX trademark), orother multi-lobular aperture or the like.

As shown in dotted lines in FIG. 11, prior to the polyaxial bone screwassembly 1 being placed in use according to the invention, the retainingring 8 is typically first inserted or top-loaded, into the head U-shapedchannel 38, and then into the cavity 47 to dispose the retaining ring 8within the inner surface 48 of the head 7. As shown in FIG. 11, theretaining ring outer edge defined by the top surface 58 slides along theinner surface 48 until the top surface 58 clears the shoulder 50. Then,the retaining ring 8 is turned so as to be coaxial with the head 7 (theAxis C aligned with the Axis B), the top surface 58 facing the channel38, and the surface 65 seated upon and in sliding engagement with theseating surface 49 as shown in solid lines in FIG. 2.

With reference to FIG. 12, the shank upper end 25 is then inserted orbottom-loaded into the head 7 through the bore 52 defined by the neck54. The retaining ring 8, now disposed in the head 7 is coaxiallyaligned with the shank capture structure 21 at the upper end 25, so thatthe dome 29 passes through the bore 57 and the ring inner surface 60 isslidingly mated to the cylindrical surface 30 of the capture structure21.

As shown in FIG. 12, the retaining ring 8 is preferably pushed upwardlyinto abutment with the shoulder 50 of the head 7 to provide ease ininstallment of the nut 9. The nut 9 is then downloaded through thechannel 38 of the head 7, also as shown in FIG. 12, and then rotatinglymated with the helical thread 24 on the capture structure 21 of theshank 6, until the nut 9 abuts against the top surface 58 of theretaining ring 8. The position of the nut 9 on the shank 6 is then fixedby inserting the set tool (not shown) between the upstanding arms 34 and35 of the head 7 and pushing against the nut 9 with the set tool tip atthe weakened area 61, the tip indenting the area 61 and also pressingagainst the threads 12 and 24, creating a deformed thread portion orarea, locking the nut 9 to the capture structure 21, which in turnlodges the ring 8 in a fixed position with respect to the shank 6. Thedeformed thread portion or portions prevent counter-clockwise rotationof the nut 9 with respect to the capture structure 21, and thus preventsthe nut 9 and the ring 8 from migrating up and off the shank upper end25.

At this time the shank 6 is in slidable and rotatable engagement withthe head 7, while the capture structure 21, the nut 9 and the retainingring 8 cooperate to maintain the shank body 15 in rotational relationwith the head 7. Only the retaining ring 8 is in slidable engagementwith the head spherical seating surface 49. Both the capture structure21 and the threaded portion of the shank body 15 are in spaced relationwith the head 7. The shank body 15 can be rotated through a substantialangular rotation relative to the head 7, both from side to side and fromfront to rear so as to substantially provide a universal or ball jointwherein the angle of rotation is only restricted by engagement of theneck 20 of the shank 6 with the neck 54 defining the bore 52 of thehead. An example of such rotation is shown in FIG. 38. The bevel 55provides for a slight increase in the extent of angular rotation of theshank body 15 with respect to the head 7.

The present invention is not intended to be restricted to a particulartype of bone screw or bone screw closure mechanism. In the presentembodiment, a polyaxial type bone screw 1 is utilized wherein the shank6 is locked in position by direct contact with the rod 3. It is foreseenthat the tool set T of the present invention can be used with virtuallyany type of bone screw, including fixed monoaxial and polyaxial bonescrews of many different types wherein the head is locked relative tothe shank by structure other than in the manner described in theillustrated embodiment.

The tool set T according to the invention typically includes at leastone, but typically a pair of end guide tools 109 and up to a pluralityof intermediate guide tools 110, each guide tool mateable with the bonescrew 1 at the apertures 44. The guide tools 109 and 110 are alsomateable with a driver 112 for implanting the bone screws 1 intovertebrae 2 of the patient's spine 4. The tool set T also includes a rodpusher 114, also mateable with the guide tools 109 and 110. Theillustrated tool set T further includes an implant fastener manipulationtool 118, a torquing tool 122 and a cooperating anti-torque tool 124,each of which cooperates with both the guide tools 109 and 110.

As illustrated in FIG. 29, a tool set T of the illustrated embodimentmay include a pair of end guide tools 109 and a pair of intermediateguide tools 110 disposed between the end guide tools 109 along a portionof a patient's spine 4, each guide tool 109, 110, attached to a bonescrew 1. But it is noted that according to the invention, none, one ormany intermediate guide tools 110 may be used, depending upon theparticular application, so that one intermediate guide tool 110 is usedfor each intermediate bone screw 1 to which the rod 3 is to be attached.Rods 3 or other longitudinal members are often installed on both sidesof the spine 4 during the same procedure.

The end guide tool 109 is illustrated in FIGS. 1-3, 22, 29, and 34-37.The elongate end guide tool 109 is somewhat cylindrical in outerprofile. With respect to inner profile, the guide tool 109 forms achannel 126 with an elongate lateral opening of various widths,configured to receive, contain and allow translational movement alongthe channel 126, or rotational relative movement of certain tools, asdescribed more fully below. The channel 126 extends from a top 128 to abottom 129 of the guide tool 109, parallel to a central axis of rotationD thereof. The channel 126 is sized to accommodate elongate tools andbone screw components, such as the fastener or closure top 10.

In particular, each end guide tool 109 has an elongate body that issized and shaped to be sufficiently long to extend from implanted bonescrews 1 through an exterior of a patient's skin 130 so as to provide anoutwardly extending and upper handle portion 132 that allows andprovides for gripping by a surgeon during procedures utilizing the toolset T, with or without an attached driver 112 or rod pusher 114.

Each of the end guide tools 109 further includes an intermediate portion134 and a lower implant engaging portion 136 which includes opposedimplant engaging members for securing an implant or bone screwtherebetween.

Each end guide tool 109 upper or handle portion 132 has a back wall witha substantially flat portion 138 joining a pair of substantiallycylindrically shaped side walls 140 and 142. A lateral, generallyelongate and axially extending opening 144 communicates with the channel126, and opens at the top 128, forming a U-shaped cross-section, aC-shaped cross-section, a crescent shaped cross-section or the like,having a side-to-side width W near the top 128. The opening 144 widensto a side-to-side width of W′ in a mid-section of the handle portion132, substantially narrows to a side-to-side width of W″ and then widensagain to the width W at a lower section of the upper handle portion 132.

Along the length of the intermediate portion 134 and the implantengaging portion 135, the opening 144 has a substantially constantside-to-side width of W, and opens at the bottom 129. The width W ispreferably slightly larger than a diameter of the rod or longitudinalmember 3. The opening 144 is also preferably sufficiently wide tointermittently receive additional tools and/or a fastener, such as theclosure top 10 for sideways loading into the channel 126.

Disposed on either side of the opening 144 are the substantiallycylindrical side walls 140 and 142. On either side of the narrowestwidth W″, are co-planar surfaces 148 and 150 integral to the walls 140and 142, respectively. The co-planar surfaces 148 and 150 are parallelwith the flat back wall surface portion 138. Although not required forthe illustrated embodiment, it is foreseen that the surfaces 140 and142, as well as the back wall portion 138, provide alignment surfaceswhen the guide tool 109 is utilized with other tools, such as certainbone screw drivers and rod pushers also having flat cooperatingsurfaces.

The upper handle portion 132 also includes an outer helically wounddiscontinuous guide and advancement structure 152 disposed on outersurfaces of both of the substantially cylindrically shaped side walls140 and 142, which may include conventional helically wound V typethreads, buttress threads, helically wound square threads, or otherguide and advancement structure to cooperate with equivalent or mateablestructure within the driver 112 and the rod pusher 114, as describedmore fully below. The guide and advancement structure 152 extends fromnear the intermediate portion 134 to the top or upper end 128. Thelateral opening 144 has the width W at the termination 154 of the guideand advancement structure 152. The back wall portion 138 extendingbetween the threaded side walls 140 and 142 has an outer substantiallyplanar and smooth surface finish.

In the intermediate portion 134 of the end guide tool 109, thesubstantially cylindrical side walls 140 and 142 include an outerradially extending bevel 156 transitioning into substantiallycylindrical side walls 160 and 162 integral with the walls 140 and 142,respectively. The walls 160 and 162 uniformly increase the thickness ofthe respective side walls 140 and 142, resulting in a substantiallycylindrical cross-section of greater outer diameter than a diametercreated by an outer surface of the side walls 140 and 142 extending fromthe top 128 to the bevel 156. The walls 160 and 162 are configured withco-planar front facets 164 and 166, respectively, providing foralignment and mating with other tools, if desired.

Near the end or bottom 129 of each end guide tool 109, disposed on innersurfaces 168 and 170 of the side walls 160 and 162 respectively, is aradially inwardly extending, implant engaging, attachment structure,generally 172, illustrated in FIGS. 7-9 and described herein withrespect to the identical structure 172 on the intermediate guide tool110. Unless specifically stated otherwise, the intermediate guide tool110 includes structure and features that can be utilized in similarfashion to what is described herein with respect to the end guide tool109, and visa-versa.

The flat back wall portion 138 disposed primarily in the upper handleportion 132 terminates at an area 176 below and spaced from the guideand advancement structure 152 in the intermediate portion 134. Also atthe area 176, the flat wall 138 forms a substantially circular aperture178 communicating with a narrow elongate slot 180 that extends from theaperture 178 to a rod abutment opening 182 disposed near the base orbottom 129. The slot 180 has a side-to-side width that is substantiallysmaller than a diameter of the rod 3. The aperture 178, the narrow slot180 and the opening 182 all communicate with the channel 126. Theopening 182 further communicates with a base opening 184 that alsocommunicates with the channel 126 and an exterior of the base 129. Theaperture 178, slot 180 rod abutment opening 182 and base opening 184,along with the channel opening 144 disposed opposite thereto, allcooperate to allow for a spreading or splaying of the side walls 160 and162 to provide a snap-on, snap-off cooperation between the implantengagement structure 172 and apertures 44 of the bone screw 1, as willbe described more fully below.

Also in the vicinity or area 176 of the aperture 178, specifically, nearwhere the aperture 178 communicates with the slot 180, the cylindricalside walls 140 and 142 each extend radially about a lower portion of theaperture 178 and towards one another, separated by the narrow slot 180.Similarly, the thicker side walls 160 and 162 disposed below the bevel156 also are separated by the narrow slot 180.

Curved surfaces 188 and 190 at lower ends of the wall portions 160 and162, respectively, define the opening 182 and are sized and shaped tofit about a portion of the cylindrical surface 66 of the rod 3. Disposednear the openings 182 and 184, and partially defining the bottom 129 isa rigid, laterally extending rod holding structure, generally 192,configured so that an end 193 of the rod 3 can extend beyond the bonescrews 1 while abutting and being held in place by the holding structure192, keeping the rod 3 in a desired position and under control. The rodholding structure 192 is generally disposed opposite the channel opening144 and includes spaced arms 194 and 196 disposed on wall portions 160and 162, respectively, sized and shaped to extend or wrap about the end193 of the rod 3, as illustrated in FIGS. 34 and 37, with the rod end193 abutting against the arms 194 and 196, and also extending outwardlybeyond the surfaces 188 and 190. In addition to extending laterallyopposite the channel opening 144, outside surfaces of the arms 194 and196 extend radially outwardly at the walls 160 and 162, forming a ledge198 that provides a stop for the rod pusher 114 and a seat for theanti-torque tool 124, as described more fully below. The arms 194 and196 maintain the rod 3 at a desired location with respect to the bonescrew 1, as well as controlling the lateral movement of the rod withrespect to the intermediate tools 110, the other end tool 109, andrespective cooperating bone screws 1.

Each of the intermediate guide tools 110, specifically illustrated inFIGS. 4 to 6, have a somewhat similar overall shape when compared to theend guide tools 109 in that both are preferably of the same axial lengthand width and also have much structure in common, with differences notedherein. With respect to inner profile, the guide tool 110 forms achannel 200 with an elongate lateral opening 202 of various widths,configured to receive, contain and allow translational movement alongthe channel 200, or rotational relative movement of certain tools, asdescribed more fully below. The channel 200 extends from a top 204 to abottom 205 of the guide tool 110, parallel to a central axis of rotationE thereof. The channel 200 is sized to accommodate elongate tools andbone screw components, such as the fastener or closure top 10.

Each intermediate guide tool 110 has an overall elongate body with anupper handle portion 206, an intermediate portion 208 and a lowerimplant engaging portion 210 which includes the structure 172 withopposed implant engaging members for securing one of the implantstherebetween. In the upper portion 206, the tool 210 is generallyC-shaped in cross-section. Each intermediate guide tool 110 upper orhandle portion 106 has a substantially flat back wall 212 joining a pairof substantially cylindrically shaped side walls 214 and 216 separatedby the axially extending channel opening 202. Similar to the opening 144of the end guide tool 109, the opening 202 has a side-to-side width Wnear the top 204 that widens to the side-to-side width of W′ in amid-section of the handle portion 206, substantially narrows to theside-to-side width of W″ and then widens again to the width W at a lowersection of the upper handle portion 206.

Disposed on either side of the opening 202 at the width W″ are co-planarsurfaces 218 and 220 that are parallel with the back wall 212. It isforeseen that the surfaces 218 and 220, as well as the back or rear wall212 may provide alignment surfaces when the intermediate guide tool 110is utilized with other tools, such as certain drivers and rod pushersthat also have flat cooperating surfaces. Below the surfaces 218 and220, the side-to-side opening width W of the lateral opening 202 issubstantially constant through the intermediate portion 208 and lowerportion 210.

The upper or handle portion 206 also includes an outer helically wounddiscontinuous guide and advancement structure 222 disposed on outersides of both of the substantially cylindrically shaped side walls 214and 216, which may include conventional helically wound V-threads,helically wound square threads, buttress threads or other guide andadvancement structure to cooperate with equivalent or mateable structurewithin the rod pusher 114 and the driver 112 as described more fullybelow. The guide and advancement structure 222 extends from near theintermediate portion 208 where the opening 202 has the width W″ to thetop 204. An outer surface of the rear or back wall 212 extending betweenthe threaded side walls 214 and 216 is substantially planar and smooth.

The back wall 212 terminates at the intermediate portion 208,specifically at a location 224 where a lateral opening 226 begins andthen extends from the location 224 to the bottom 205 of the tool 110.The opening 226 is open at the bottom 205, disposed opposite the opening202, communicates with the channel 200, and also has the side-to-sidewidth W. Thus, the openings 202 and 226 form a through-slot, dividingthe side walls 214 and 216 into legs or prongs 228 and 230,respectively. The legs 228 and 230 have outer surfaces that aresubstantially cylindrical.

In the intermediate portion 208 of the guide tool 110, the legs 228 and230 include an outer radially extending bevel 232 transitioning intosubstantially cylindrical side legs 234 and 236 integral with the legs228 and 230, respectively. The legs 234 and 236 uniformly increase thethickness of the respective legs 228 and 230, resulting in asubstantially cylindrical cross-section of greater outer diameter than adiameter created by an outer surface of the side walls 214 and 216, orthe legs 228 and 230. At the base 205, both the legs 234 and 236 taperslightly radially inwardly, forming a bevel 237. The legs 234 and 236also are configured with co-planar front facets 238 and 240,respectively, and rear facets 242 and 244, respectively, providing foralignment and mating with other tools, if desired.

With reference to FIGS. 7-9, at the lower portion 210, along innersurfaces 246 and 248 of the legs 234 and 236, respectively, is disposedthe implant engaging structure, generally 172. The implant engagingstructure 172 includes diametrically opposed projections or pins 250 and252, both extending radially inwardly from the surfaces 246 and 248,respectively. The pins 250 and 252 are substantially configured thesame, both being substantially rounded, radially inward projectingnodules, each having a lip 254 projecting upwardly and away from thebottom 205. Each lip 254 partially defines a groove 256 for receivingthe bone screw 1. The groove 256 is further defined by a base surface258 and a recessed wall 260. An upper wall 262 that is substantiallyparallel to the base surface 258 spans between the recessed wall 260 andthe inner surface 246 or the inner surface 248.

With reference to FIGS. 13-15, the pins 250 and 252 are configured tomate with the opposed apertures 44 of the bone screw 1 with the lip 254extending into the inner recess 45, when the guide tool 110 is fullyinstalled on the bone screw head 7 as shown in FIG. 15 and describedmore fully below. While a preferred embodiment of the invention has pins250 and 252 of the implant engaging structure 172 on the guide tools 109and 110, and apertures 44 and 45 on the bone screw heads 7, it isforeseen that these elements could be reversed in total or part inaccordance with the invention or that other suitable attachmentstructure could be used.

With reference to FIGS. 16-18, the driver 112 of the tool set T of theinvention includes a handle 270, a guide tool fastener or nut 272, andan elongate cylindrical stem or shaft 274, tapering to an integral lowercylindrical portion 275 having an inner surface bone screw engaging,socket structure 276. The socket 276 is configured to mate with theupper part of the nut 9 attached to the bone screw shank 6. The shaft274 with attached socket 276 is receivable in and passes through theinterior of the guide tools 109 and 110, such as the channel 200 of theguide tool 110. The lower portion 275 has a slightly smaller diameterthan a diameter of the remainder of the shaft 274, this smaller diameterprovides for adequate clearance of the portion 274 from the bone screwguide and advancement structure 42 when the shaft 274 is installedwithin the interior of the respective guide tools 109 and 110 andbetween the bone screw arms 34 and 35. The stem or shaft 274 is rigidlyattached to the handle 270 and coaxial therewith. Both the handle 270and the guide tool fastener 272 include outer grooves 278 and 279respectively, about outer cylindrical surfaces thereof to aid ingripping and rotating the respective components.

The guide tool fastener 272 is a substantially hollow cylinder disposedin coaxial relationship with the handle 270 and the shaft 274. Thefastener 272 has a threaded inner cylindrical surface 282 disposed at alower portion 283 thereof, the threaded surface 282 configured to matewith the guide and advancement structure 152 of the end guide tool 109or the guide and advancement structure 222 of the intermediate guidetool 110.

The driver 12 further includes a lateral pin 286 projecting radiallyoutwardly from a cylindrical surface 288 adjacent the handle 270. In theembodiment shown, the cylindrical surface 288 is integral with thehandle 270 and fixedly attached to the shaft 274. The pin 286 isdisposed within an annular recess 290 defined by the cylindrical surface288, and surfaces of the fastener 272, including an upper seatingsurface 292, a lower seating surface 294 and an inner cylindricalsurface 296. The pin 286 disposed in the recess 290 allows for bothrotational and axial or vertical translational movements of the fastener272 with respect to the handle 270 and the shaft 274. Thus, as shown inFIG. 18, the fastener 272 is freely rotatable about an axis Findependent of the shaft 274. Furthermore, the fastener is slidablealong the axis F, with FIG. 16 showing a first or unattached positionwith the fastener 272 in contact with the handle 270 and FIGS. 17 and 18showing a second, engagement position, with the fastener 272 spaced fromthe handle 270, with the pin 286 abutting the upper seating surface 292prohibiting further downward or vertical (axial) translational movementof the fastener 272 with respect to the shaft 274.

The driver 112 is sized and shaped such that, when the fastener or nut272 is slid into the second position shown in FIGS. 17 and 18 and thefastener threaded surface 282 is mated with the guide and advancementstructure 152 of the end guide tool 109 or the guide and advancementstructure 222 of the intermediate guide tool 110 as shown in FIG. 19, byrotating the fastener 272 in a clockwise direction, the socket 276descends upon and engages with the outer surface of the nut 9 as shownin FIGS. 20 and 21. When the socket 276 abuts against the retaining ringtop surface 58, and the fastener nut 272 is fully mated to the guidetool 109 or 110, relative axial movement between the driver 112 and theguide tool 109 or 110 is prevented. However, the driver handle 270 andattached stem 274 are freely rotatable with respect to the fastener 272about the Axis F, and the bone screw nut 9 and attached bone screw shank6 also are freely rotatable with respect to the bone screw head 7 andattached guide tool 109 or 110, about the Axis A, which is coaxial withthe Axis F. Thus, the driver 112 and engaged bone screw shank 6 may berotated and the shank body 15 driven into a vertebra 2 as shown in FIG.22 and discussed more fully below, while the bone screw head 7 iscontrolled and held in a stable, non-rotating position by thenon-rotating guide tool 109 or 110. After the bone screw shank body 15is driven into bone, the driver 112 may be easily removed from the guidetool 109 or 110 by rotating the fastener 272 in a counter-clockwisedirection and lifting the driver 112 away and out of the guide tool 109or 110.

The rod pusher 114 of the tool set T is illustrated in FIGS. 23-25 and27-31. With particular reference to FIGS. 23-25, the rod pusher 114 iselongate and substantially cylindrical, having an upper handle portion300, a sleeve 302 and a lower rod-engaging portion 304. An open innerchannel 306 extends from a top 308 to a bottom 310 of the rod pusher114. The rod pusher 114 is configured to closely receive a guide tool109 or 110 within the channel 306 as illustrated in FIGS. 27-31.

The upper handle portion 300 has a cylindrical outer surface that hasouter grooves 312 to aid in gripping and rotating the rod pusher 114.The upper handle portion also has a substantially cylindrical, threaded,inner surface 314, configured to mate with either the guide andadvancement structure 152 of the end guide tool 109 or the guide andadvancement structure 222 of the intermediate guide tool 110. Thethreaded surface 314 extends from the top 308 to a location 316 wherethe handle portion 300 integrally connects with the sleeve 302.

The sleeve 302 includes an outer cylindrical surface 318 and an innercylindrical surface 320, substantially removed by an elongatethrough-slot 322, partially defined by a U-shaped top 324 and a U-shapedbottom 326. The U-shaped bottom 326 is spaced from the rod pusher bottom310. The lower rod-engaging portion 304 is substantially cylindrical,integral with the sleeve 302 and extends from the bottom 310 to theU-shaped bottom 326 of the through-slot 322. A cylindrical inner surface328 at the rod-engaging portion 304 is integral and coaxial with thesleeve inner surface 320, which in turn is integral and coaxial with theinner threaded surface 314. The inner surfaces 320 and 328 areconfigured to closely receive and contain the guide tool 109 at thethick side walls 160 and 162 and the guide tool 110 at the legs 234 and236. The rod pusher 114 is configured to be received about the guidetool 109 or 110, with the substantially circular bottom 310 pressingagainst the outer cylindrical surface 66 of the rod 3 at either side ofthe guide tool 109 or 110, as shown, for example in FIG. 29. Clock-wiserotation of the rod pusher 114 about the guide tool 109 or 110 causesthe threaded surface 314 to mate with either the guide and advancementstructure 152 or the guide and advancement structure 222, and continuedrotation translates the rod pusher bottom surface 310 downwardly, towardthe bone screw 1 as shown in both FIGS. 29 and 30. The inner threadedsurface 314 is of a length that provides an equivalent translationdistance of the rod pusher bottom 310, so that the bottom istranslatable along the guide tool 109 or 110 to a location wherein therod 3 is fully seated within the bone screw 1 as illustrated in FIG. 31.

With reference to FIGS. 27-29 and 31, a three-component assembly of thetool set of the invention includes a guide tool 109 or 110, a rod pusher114 and a manipulation tool 118. The manipulation tool 118 with anattached fastener, such as the closure top 10 may also be utilized topress against the rod 3, alone or in cooperation with a rod pusher 114as shown in FIG. 29 and described more fully below. Also as shown inFIG. 29, it may be desirable to utilize only one rod pusher 114 for atool set T. In certain procedures, more rod pushers 114 may be desired.

The manipulation tool 118 includes a handle 330, fixedly attached to orintegral with an elongate stem 332 having a lower fastener engagementend portion 334. Similar to the other tools in the tool set T, thehandle 330 preferably includes outer grooves 336 to aid in gripping androtating the tool 118. The handle 330 and stem 332 are configured to bereceived by the guide tool 109 or the guide tool 110 at the channels 126and 200, respectively, with the handle 330 being closely receivedthereby so as to provide axial alignment between the tool 118 and theguide tool 109 or 110, providing efficient guidance and control of thefastener 10 into the bone screw 1. As illustrated in FIG. 28, themanipulation tool 118 is configured to have a length to allow asubstantial portion of the handle 330 disposed above the guide tool 109or 110 during attachment of the fastener 10 to the bone screw 1 for easein handling and manipulation of the fastener 10 within the channel 126or 200 and between the bone screw arms 34 and 35.

With special reference to FIG. 31, the fastener engagement end portion334 includes a projection 340 extending from a bottom 342 of the stem332 to a tapered end portion 344 receivable into the central bore 77 ofthe closure top break-off head 68. The projection 340 and tapered endportion 344 have a maximum diameter that is smaller than a maximumdiameter or width of the stem 334. Also extending from the bottom 342 ofthe stem 332 are opposed nubs 356 that are receivable in thepass-through slot 78 of the break-off head 68 at either side of theprojection 340. When inserted in the break-off head 68, the projection340 and nubs 356 cooperate to securely attach the closure top 10 to themanipulation tool 118 during insertion of the closure top 10 into theguide tool 109 or 110 and the bone screw 1, but also be easilydetachable from the bone screw 1 by pulling the tool 118 upwardlyaxially and out of the guide tool 109 or 110 once the closure top 10 isrotated and secured between the arms 34 and 35 of the bone screw head 7.

Once the closure top 10 is seated in the bone screw 1, the torquing tool122 and cooperating anti-torque tool 124 are utilized to tighten theclosure top 10 in the screw head 7 and remove the break-off head 68. Thetorquing tool 122 and anti-torque tool 124 are illustrated in FIGS.32-36. The torquing tool 122 shown in FIG. 34, includes an upper handleportion 350 disposed perpendicular to an elongate stem 352 that isintegral to a lower closure top engagement portion 354 having an innersurface defining a socket 356 configured for mating with and rotatingthe faceted surface 75 of the closure top break-off head 68. Theelongate stem 352 is configured to be received in the guide tool 109 or110, with the handle 350 at a desired height there-above to allow forsufficient mechanical advantage and ease in rotating the stem 352 to setthe closure top 10, so it is snug against the rod 3, and thereafterbreak away and remove the break-off head 68 in the manner shown in FIGS.35 and 36.

With particular reference to FIGS. 32 and 33, the anti-torque tool 124includes an elongate handle 358 fixed to a tubular hollow shaft 360 thatis sized and shaped to be slidably received over the guide tool 109 or110. The handle 358 is disposed perpendicular to the shaft 360 and hasan opening 361 through which the torquing tool 122 passes in the mannersuggested by FIG. 34. The shaft 360 has a lower end portion 362 that hasa pair of diametrically spaced, curved bridges 364 and 366. Both of thebridges 364 and 366 are sized and shaped to fit over the surface 66 ofthe rod 3 as illustrated in FIGS. 35 and 36. The curved bridge 364further includes extensions 370 that provide additional coverage aboutthe surface 66 of the rod 3 and are particularly useful for holding therod 3 in place when used with the end tool 109. A bottom surface 372adjacent the bridge 366 seats on the ledge 198 of the rod holdingstructure 192 of the end guide tool 109, while the extensions 370disposed opposite thereof, extend downwardly on either side of the rod 3and are flush with the front facets 164 and 166 of the guide tool 109.Disposed between the handle 358 and the lower end portion 362 is anelongate through-slot 374 with U-shaped ends, similar to the slot 322 ofthe rod pusher 114. When in place, as illustrated in FIGS. 35 and 36,the anti-torque tool 124 allows a surgeon to counter the torque appliedby the torquing tool 122, when applying torque to and breaking away thebreak-off head 68.

In use, the previously described tools are utilized to attach one ormore rods 3 to the human spinal column 4. The procedure is begun byselection of a bone screw 1 in accordance with the size of the patient'svertebra 2 and the requirements of the spinal support needed. Bonescrews having a rotatable or polyaxial head are preferred but notrequired for the procedure, as such allow relatively easy adjustment ofthe rod 3 in the guide tools 109 and 110 during placement and formovement of the tools 109 and 110, as described below. The bone screwmay also be cannulated so as to be receivable over and guided by a guidepin, if desired.

A relatively small incision, such as an incision 380 in the skin 130 ismade for each bone screw 1 to be used. Preferably, the incisions aresized so as to snugly receive the tools of the invention. The incisions380 are stretched into a round shape with a circumference slightlylarger than the guide tool 109 and 110. The skin 20 is relativelyflexible and allows the surgeon to move the incision 380 around relativeto the spine 4 to manipulate the various tools and implants, asrequired. In some cases, two screws can be inserted through the sameincision.

With reference to FIG. 22, guide bores may be drilled in the vertebra 2prior to implantation of bone screws 1 therein. This may be accomplishedwith non-invasive imaging techniques, which procedures are known andestablished. The guide bores are then preferably enlarged and shaped tocorrespond with the thread-type of the bone screw 1 to be used.

Before implanting the bone screw 1 in the vertebra 2, the bone screw 1is preferably joined to an associated guide tool 109 or 110 and anassociated driver 112. It is possible, but typically not desirable, tojoin a guide tool 109 or 110 to the bone screw 1 after the installationof the bone screw 1 to the vertebra 2. The implant engaging structure172 disposed on both the end guide tool 109 and the intermediate guidetool 110 is joined to a bone screw 1 by first manually spreading thewalls 160 and 162 apart; or the legs 234 and 236 apart; and insertingthe guide tool 109 or 110 onto the bone screw head 7 as illustrated inFIG. 13 with respect to an intermediate guide tool 110. The inwardlyprojecting pins 250 and 252 are generally aligned with the apertures 44and the tool is slid downwardly along the head 7 surface until the pins250 and 252 snap into the apertures 44 as shown in FIG. 14. Withreference to FIG. 15, the guide tool 110 is then pulled upwardly andaway from the bone screw 7, causing the lips 254 to enter the recesses45. Engagement between the lips 254 and the structure defining therecesses 45 result in a firm attachment that also resists any attempt tospread or splay the arms 234 and 236.

The snap-on procedure described herein with respect to the intermediatetool 110 is also followed with respect to the end guide tool 109attachment structure 172. Splaying of the walls 160 and 162 is possiblebecause the aperture 178, slot 180 and openings 182 and 184, cooperatewith the opposite channel opening 144, resulting in adequate flexibilityfor spreading or extending the opposing walls 160 and 162 about the head7 of the bone screw 1 as shown in FIG. 13. If desired, a tool may beinserted in the aperture 178 and then into the slot 180 to aid insplaying the walls 160 and 162.

After the bone screws 1 have been attached to the guide tools 109 and110, a driver 112 is then attached to the guide tool 109 or 110 forimplanting the attached bone screw 1 in a vertebra 2. With reference toFIGS. 19-21, the driver 112 is installed by inserting the socket end 276into the channel 126 or 200 of the top 128 or 204, respectively of therespective guide tool 109 or 110. The driver is then advanced down thechannel 126 or 200 until the threaded inner surface 282 of the driverfastener 272 contacts the guide and advancement structure 152 or 222 ofthe guide tool 109 or 110, respectively. Then the fastener 272 isrotated in a clockwise direction (as viewed from the top of the handle270) until there is resistance to rotation caused by the socket 272surrounding the nut 9 and abutting against the top 58 of the retainingring 8 of the bone screw 1 as illustrated in FIG. 21. A slight rotationor jiggling of the bone screw shank 6 may be required for the hex socket276 of the driver 112 to become positioned in operational engagementwith the hex-shaped facets 13 of the nut 9. Hand-tightening of thefastener 272 after the socket 272 is positioned about the nut 9,ensuring that the lips 254 of the implant engaging structure 172 areabutting against the bone screw head 7 at the inner recesses 45, thussecurely mating the bone screw 1 to the guide tool 109 or 110 during thebone screw implantation process. The assembly shown in FIG. 19 thatincludes a bone screw 1, an intermediate guide tool 110 and a driver 112is now ready for bone screw installation into the vertebra 2. FIG. 22illustrates a driver similarly installed in an end guide tool 109.

A series of bone screws 1 are installed in each vertebra 2 to beattached to the rod 3 by inserting the bone screw, guide tool andattached driver assemblies through the skin incision 380 as shown inFIG. 22. The screw 1 is then rotated and driven into a tapped bore withthe surgeon holding the guide tool 109 or 110 stationary and rotatingthe driver 112 by the handle 270, until the shank body 15 is disposed ata desired depth in the tapped bore of the respective vertebra 2.

After a specific bone screw 1 is installed, the driver 112 is removedfrom either the guide tool 109 or 110 by rotating the fastener 272 in acounter-clockwise direction and pulling the driver 112 out of theassembly and away from the incision 380 using the handle 270.

For each implanted bone screw 1, an associated guide tool 109 or 110extends through the skin 130, as illustrated in FIG. 29. An end guidetool 109 is located at each end of the series of bone screws 1 with thechannel opening 144 facing toward the intermediate guide tools 110disposed between the end guide tools 109. The intermediate guide tools110 are implanted in an alignment such that the lateral openings 202 and226 align with the channel openings 144 of the end guide tools 109.

In order to install a rod 3 in two or more bone screws 1, it may not benecessary to equip each guide tool 109 or 110 with a rod pusher 114. Forexample, with reference to FIG. 29, for a particular procedure, it maybe desirable to utilize only one rod pusher 114 with a tool set Taccording to the invention. Some pushing of the rod may be accomplishedby just extending a rod or tool down the central channel of the guidetools 109 and 110 when mechanical advantage is not required to move therod 3. As required by the surgeon, one or more rod pushers 114 may beadded or removed at any time during the course of the rod pushing orreducing procedure.

With reference to FIG. 29, the rod end 193 has been inserted diagonallythrough one of the end skin incisions 380 with the adjacent end guidetool 109 pushed to the side, so that one of the rod ends 193 firstpasses through the lateral openings 202 and 226 in the intermediateguide tools 110 and then into the lateral opening 144 of the channel 126of one of the guide tools 109. Back muscle tissue separates easily hereto allow the upper insertion of the rod 3 and can be further separatedby finger separation or cutting through one of the incisions 380, ifrequired.

After initial insertion, the remaining opposed end 193 of the rod 3 ispositioned in the channel 126 of the end guide tool 109 that is locatednext to the insertion point of the rod 3. Manipulation of the rod 3 inthe channels 126 and 200 may be aided by a manipulation tool 118 andattached fastener 10 as illustrated in FIG. 29 and also by the guidetools 109 and 110 themselves which may be moved toward or away from eachother by the surgeon. For example, when the rod 3 is spaced above thebone screws 1, the guide tools 109 can be manipulated to be spacedfarther apart to receive the rod 3 therebetween. As the rod 3 nears thebone screws 1, the rod ends 193 are slid through the rod abutmentopening 182 and into the rod holding structure 192 to allow the rod 3 toextend slightly beyond the bodies of the guide tools 109. The rodholding structures 192 allow the rod 3 to be controlled and positionedoutwardly of the end bone screws 1, approximately an equal amount oneach side.

Also with reference to FIG. 29, once the rod 3 is positioned in theguide tools 109 and 110, the rod pusher 114 may be utilized to push therod 3 toward the bone screw 1, normally when mechanical advantage isneeded to seat the rod 3 in the bone screws 1. In the illustratedembodiment, this is accomplished by inserting the rod pusher 114 over anintermediate guide tool 110 and then rotating the rod pusher 114 in aclockwise direction (as viewed from above the skin 130), mating thethreaded inner surface 314 with the guide and advancement structure 222,thereby translating the sleeve 302 in a downward direction toward thebone screw 1, with the rod pusher bottom 310 abutting and pushingagainst the rod 3.

As shown in FIG. 29, it may also be desirable to simultaneously orthereafter push the rod 3 toward the screw 1 of one or more guide tools109 and 110 utilizing the manipulation tool 118 pushing against aclosure top 10 that in turn pushes against the rod 3. In particular, aclosure top 10 is attached to the manipulation tool 118 with theprojection 346 of the tool inserted into the central bore 77 of theclosure top 10 and the nubs 346 inserted into the grooves 78. Then theclosure top 10 is inserted into the channel 126 or 200 of the guide tool109 or 110, respectively, by top entry or side entry through therespective lateral channel opening 144 or 202. If the rod pusher 114 isbeing utilized on the guide tool 109 or 110, then entry though therespective top 128 or 204 would be necessary. If desired, the closuretop 10 may first be inserted in the guide tool 109 or 110 by top or sideentry and then the manipulation tool 118 may be inserted into the topand moved through the channel 126 or 200 until the fastener engagementend 334 mates with the cooperating break-off head 68 of the closure top10. The closure top 10 is then pushed under manual control of thesurgeon holding the handle 330 of the manipulation tool 118.

With reference to FIG. 31, when the closure top 10 guide and advancementstructure 71 abuts against the guide and advancement structure 42 on theinner surface of the head 7 of the bone screw 1, the manipulation tool118 is then rotated, mating the closure top 10 with the bone screw 1 anddriving the closure top 10 downward against the rod 3 to urge the rod 3into final placement in the bone screw U-shaped channel 38 so as to snugagainst and frictionally lock the shank 6 in position relative to thebone screw head 7. As shown in FIG. 31, the manipulation tool 118 isthen pulled axially upwardly away from the bone screw 1 and out of theincision 380.

Once all of the closure tops 10 are in a final seated position inrespective bone screws 1 and the surgeon is satisfied with the positionof all of the elements, any and all rod pushers 114 are removed byrotating the rod pusher 114 counter-clockwise followed by sliding thesleeve 302 off of the guide tool 109 or 110 and out of the incision 380.

The anti-torque tool 124 is mounted over each guide tool 109 and 110,utilizing the respective guide tool as a guide for re-entry through theincision 380. With respect to the end tool 109, the anti-torque tool 124is slid along the tool 109 until the bridges 364 and 366 straddle therod 3, with the bridge 366 disposed over the rod holding structure 192at the back of the tool 109 and the extensions 370 straddling the rodadjacent the lateral opening 144 at the front thereof, the bridges 364and 366 cooperating to prevent rotation of the tool 124. The bottomsurface 372 of the anti-torque tool 124 also seats on the ledge 198 ofthe rod holding structure 192, providing increased stability. When theanti-torque tool is placed on an intermediate guide tool 110, thebridges 364 and 366 are simply aligned with and placed over the rod 3,without reference to a front or back of the tool 110.

With reference to FIGS. 34-36, the torquing tool 122 is then insertedinto the guide tool 109 or 110 and cooperating anti-torque tool 124 andengaged with the break-off head 68. By cooperative use of the tools 122and 124, a preselected torque is manually applied to the break-off head68 which breaks from the closure top 10 as illustrated in FIGS. 35 and36 and is thereafter removed, followed by removal of the anti-torquetool 300.

Thereafter, each of the guide tools 109 and 110 are removed from theattached bone screws 1. With respect to the end guide tool 109, downwardforce is first placed on the guide tool 109 by the surgeon to move thelips 254 of the guide tool implant engaging structure 172 out of theinner recesses 45 of the bone screw head 7. Then a prying tool may beinserted in the aperture 178 and then along the slot 180 to spread theside walls 160 and 162, while pulling up on the guide tool 109 to allowthe guide tool to slide upwardly along the bone screw head 7 (asillustrated in reverse by FIGS. 15, 14 and 13).

Similarly, with respect to the intermediate guide tools 110, downwardforce is first placed on the guide tool 110 by the surgeon to move thelips 254 of the guide tool implant engaging structure 172 out of theinner recesses 45 of the bone screw head 7. Then a prying tool may beinserted between the legs 228 and 230 to spread the lower legs 234 and236, while pulling up on the guide tool 110 to allow the guide tool toslide upwardly along the bone screw head 7 (as illustrated in reverse byFIGS. 15, 14 and 13).

The guide tool 109 or 110 is then pulled axially upwardly away from thebone screw 1, and then out of the incision 350. Finally, the incision isclosed.

It is to be understood that while certain forms of the present inventionhave been illustrated and described herein, it is not to be limited tothe specific forms or arrangement of parts described and shown.

1. An apparatus for implanting a rod in a spinal bone anchor located ina patient, the apparatus comprising: a) a first tool portion having: i)an elongate body having a longitudinal axis, a central bore extendingalong the longitudinal axis an entire length of the body, an outersurface and a first channel with a lateral opening extending through theouter surface from a bottom of the body along a substantial length ofthe body, the first channel and the lateral opening being sized andshaped to receive a rod therein, ii) a spinal bone anchor engagingstructure near a bottom of the body that is adapted for removablyattaching the first tool portion to a bone anchor such that the centralbore is centered over a rod-receiving second channel in a head of thebone anchor and the central bore and the first channel and the channellateral opening become aligned with the rod-receiving second channel;and iii) an elongate narrow slot disposed opposite the lateral openingand extending upward from the bottom of the body to an intermediateportion of the body, the narrow slot and lateral opening cooperating toallow manual flexing of the elongate body so as to enlarge the boneanchor engaging structure and thereby enable a snap-on relation of thebone anchor to the bone anchor engaging structure; and b) a second toolportion cooperating with the first tool portion to reduce the rodrelative to the bone anchor rod-receiving second channel so as to seatthe rod in the rod-receiving second channel and thereafter the first andsecond tool portions cooperating to facilitate insertion of a fastenerfor locking the rod within the bone anchor rod-receiving second channel,and thereafter the apparatus is removed from the patient.
 2. Theapparatus of claim 1 further including: a) a rigid holding structuredisposed opposite the lateral opening and near the bottom of the bodyand projecting laterally outwardly from the elongate body outer surface,the holding structure sized and shaped to closely receive and abutagainst an end of the rod; wherein b) the rigid holding structure issized and shaped to hold the rod end at a location outside of the boneanchor.
 3. The apparatus of claim 2 wherein the rigid holding structureincludes a pair of spaced arms extending about the body, the body havingan opening disposed adjacent the arms, the opening sized and shaped toreceive the rod therethrough.
 4. The apparatus of claim 1 wherein thebone anchor engaging structure includes first and second opposed pinsprojecting into the central bore, the pins sized and shaped to bereceived in cooperating apertures in the bone anchor for releasableattachment thereto.
 5. The apparatus of claim 4 wherein each pin has anupwardly projecting lip sized and shaped to be received in an upwardlyprojecting inner recess of the bone anchor apertures.
 6. The apparatusof claim 4 wherein flexing of the elongate body increases a distancebetween the first and second pins during insertion of the first toolportion on the bone anchor, the pins being in inwardly biasing snap-onrelation to the bone anchor at the bone anchor apertures.
 7. Theapparatus of claim 1 further comprising a driving tool separatelyattachable to the first tool portion, the driving tool receivable in thecentral bore and operably attachable to the bone anchor for rotating anddriving the bone anchor into bone.
 8. The apparatus of claim 7 whereinfirst tool portion has an outer guide and advancement structure and thedriving tool has a fastener, a stem and a driving structure disposed ata lower end of the stem, the driving structure for rotating and drivingthe bone anchor into bone, the fastener having an inner guide andadvancement structure, the fastener being freely rotatable with respectto the stem and the inner guide and advancement structure and rotatinglymateable with the outer guide and advancement structure.
 9. Theapparatus of claim 8 wherein the driving structure is an internalsurface forming a socket for receiving an upper portion of the boneanchor.
 10. The apparatus of claim 1 further comprising a rod pusherseparately attachable to the first tool portion, the rod pusher having asleeve and a driving end, the sleeve receivable over the first toolportion elongate body and operably attachable to the elongate body forrotating thereabout, with the rotational movement of the sleeve alsotranslating the driving end along the elongate body.
 11. The apparatusof claim 10 wherein the first tool portion has an outer guide andadvancement structure and the rod pusher has an inner guide andadvancement structure mateable to the outer guide and advancementstructure.
 12. The apparatus of claim 1 further comprising a) anelongate torquing tool having a handle and a stem receivable in thecentral bore of the first tool portion and attachable to a bone anchorfastener; and b) an elongate anti-torque tool having a handle and asleeve receivable over the elongate body of the first tool portion, thesleeve sized and shaped to seat upon and abut against a rod at eitherside of the first tool portion elongate body, precluding any rotationalmovement of the anti-torque tool relative to the first tool portion. 13.The apparatus of claim 1 further comprising at least one intermediateguide tool having first and second elongate legs defining an elongatethrough-slot sized and shaped for receiving a rod therethrough, and asecond opposed bone anchor engaging structure disposed near a bottom ofthe legs.
 14. The apparatus of claim 13 wherein the second bone anchorengaging structure includes third and fourth opposed pins, the third pindisposed on the first leg and the fourth pin disposed on the second leg,the third and fourth pins projecting inwardly from the respective legsand sized and shaped to be received in cooperating apertures in a boneanchor for releasable attachment thereto.
 15. The apparatus of claim 14wherein the through-slot is sized and shaped to allow for manual flexingof the intermediate guide tool legs to increase a distance between thethird and fourth pins during insertion of the intermediate guide tool onthe bone anchor, the third and fourth pins being in inwardly biasingsnap-on relation to the bone anchor at the bone anchor apertures. 16.The apparatus of claim 15 wherein the third and fourth pins each have anupwardly projecting lip sized and shaped to be received in an upwardlyprojecting inner recess of the bone anchor apertures.
 17. The apparatusof claim 13 further comprising a driving tool attachable to theintermediate guide tool, the driving tool receivable in the through-slotand operably attachable to the bone anchor for rotating and driving thebone anchor into bone.
 18. The apparatus of claim 13 further comprisinga rod pusher attachable to the intermediate guide tool, the rod pusherhaving a sleeve and a driving end, the sleeve receivable over the firstand second legs and operably attachable at an upper end of theintermediate guide tool for rotating thereabout, with the rotationalmovement of the sleeve also translating the driving end along the firstand second legs.
 19. The apparatus of claim 13 further comprising a) anelongate torquing tool having a handle and a stem receivable in thethrough-slot of the intermediate guide tool and attachable to an implantfastener; and b) an elongate anti-torque tool having a handle and asleeve receivable over the first and second legs of the intermediateguide tool, the sleeve sized and shaped to seat upon and abut against arod at either side of the intermediate guide tool body, precluding anyrotational movement of the anti-torque tool relative to the intermediateguide tool.
 20. A tool set for implanting a rod in a spinal bone anchorlocated in a patient, the tool set comprising: a) a first tool portionhaving: i) an elongate body having a longitudinal axis, a central boreextending along the longitudinal axis an entire length of the body, anouter surface and a channel with a lateral opening and a narrow rearslot extending through the outer surface from a bottom of the body alonga substantial length of the body, the channel and the lateral openingbeing sized and shaped to receive a rod therein, the slot and thelateral opening cooperate to allow manual flexing of the body; and ii) aspinal bone anchor engaging structure near a bottom of the body that isadapted for removably attaching the first tool portion to a bone anchorsuch that the central bore becomes aligned with a rod-receiving channelin the bone anchor; wherein iii) the manual flexing of the body enlargesthe bone anchor engaging structure, so as to allow the bone anchorengaging structure to snap on to the bone anchor; and b) a second toolportion cooperating with the first tool portion to reduce the rodrelative to the bone anchor rod-receiving channel so as to seat the rodin the rod-receiving channel and thereafter the first and second toolportions cooperating to facilitate insertion of a fastener for lockingthe rod within the bone anchor rod-receiving channel, and thereafter thefirst and second tool portions are removed from the patient.
 21. Anapparatus for implanting a rod in a spinal bone anchor located in apatient, the apparatus comprising: a) a first tool portion having: i) anelongate body having a longitudinal axis, a central bore extending alongthe longitudinal axis an entire length of the body, an outer surface anda channel, the channel having a lateral opening and an opposed narrowslot, each of the lateral opening and the slot extending through theouter surface from a bottom of the body along a length of the body, thechannel and the lateral opening being sized and shaped to receive a rodtherein; and ii) a spinal bone anchor engaging structure near a bottomof the body that is adapted for removably attaching the first toolportion to a head of the bone anchor such that the tool body centralbore is centered over a rod-receiving channel in the head of the boneanchor and the central bore and a central bore in the head of the boneanchor become axially aligned and the lateral opening in the tool bodybecomes aligned with the rod-receiving channel in the bone anchor head;the slot and the elongate channel cooperating to enlarge the bone anchorengaging structure by manual flexing of the body, whereby the boneanchor engaging structure snaps on to the bone anchor head; and b) asecond tool portion cooperating with the first tool portion to reducethe rod relative to the bone anchor head rod-receiving channel so as toseat the head rod in the rod-receiving channel and thereafter the firstand second tool portions cooperating to facilitate insertion of afastener for locking the rod within the bone anchor head rod-receivingchannel, and thereafter the apparatus is removed from the patient.
 22. Atool set for implanting a rod in a spinal bone anchor located in apatient, the tool set comprising: a) a first tool portion having: i) anelongate body having a longitudinal axis, a central bore extending alongthe longitudinal axis an entire length of the body, an outer surface anda body channel with both a lateral opening an opposed narrow slotextending through the outer surface from a bottom of the body along alength of the body, the body channel and lateral opening being sized andshaped to receive a rod therein, the lateral opening and the narrow slotcooperating to enable manual flexing of the body and a snap-on relationof the body with a bone anchor; and ii) a spinal bone anchor engagingstructure near a bottom of the body that is adapted for removablyattaching the first tool portion to the bone anchor such that thecentral bore becomes axially aligned with a central bore in a head ofthe bone anchor and the body channel becomes aligned with arod-receiving channel in the head of the bone anchor; b) a second toolportion cooperating with the first tool portion to reduce a rod relativeto the bone anchor rod-receiving channel so as to seat the rod in therod-receiving channel of the head of the bone anchor and thereaftercooperating with at least the first tool portion to facilitate insertionof a fastener for locking the rod within the bone anchor rod-receivingchannel, and thereafter the first tool portion being detached from thebone anchor and removed from the patient.